Holding altcoins in a long term will be effective only if it has a potential to increase in the future, or promising.
And if that happens there is a probability that you can earn big in the future, however if you hold the wrong altcoin
time will will turn into waste only, so be careful and be wise before anything else.
if I bought 1000 coins for 1 eth, then if these coins grow and my profit is 1.5 ethers, then I sell tokens for 1 eth and I leave 0.5 eth in this coin for long-term
Not bad not great. As a crypto trader, if you can increase the portfolio value and you have trading skills for boosting the crypto portfolio you are good to go. There have been a worst days and it is always possible to see a bad days but what matters is to keep faith as a crypto enthusiast. Initial investment amounts are usually higher than 1 Ethereum worth token value but this value fluctuate along with the market cycles.